Re: [Qemu-devel] State of QEMU CI as we enter 4.0

[Daniel P . Berrangé]

On Fri, Mar 15, 2019 at 09:34:27AM +0000, Alex Bennée wrote:
> 
> Daniel P. Berrangé <address@hidden> writes:
> 
> > On Thu, Mar 14, 2019 at 03:57:06PM +0000, Alex Bennée wrote:
> >> Docker Images
> >> =============
> >>
> >> The addition of docker has unlocked the ability to build a lot more
> >> tests as well as compile testing on a much wider range of distros. I
> >> think there are two outstanding areas that need improvement
> >>
> >> Daniel has been looking at building and hosting the images somewhere.
> >> This would be useful as it would stop us slamming the distros
> >> repositories constantly rebuilding the same images and also help reduce
> >> the time to test.
> >
> > My intent was/still is to make use of quay.io for hosting prebuilt
> > images.
> >
> > As well as avoiding repeated builds for developers it means that
> > developers can be gauranteed to actually be testing with the same
> > content that the automated CI did. Currently everyone using the
> > docker images potentially has slightly different environment as
> > it depends on what packages were in the repos when they built
> > the image locally. This is very bad for reproducability.
> >
> > Libvirt uses quay.io for hosting images already and I've been
> > looking at creating a script to automate usage of it via their
> > REST API. Once done the same script should be usable by QEMU
> > too.
> >
> > The idea would be that we still have docker files in the
> > tests/docker/dockerfiles directory, but they would only be used
> > for an automated job which triggers builds on quay.io, or for the
> > few people who need to make changes to the dockerfiles. The current
> > make rules used by developers / CI systems for executing test builds
> > would be changed to simply pull the pre-built image off quay.io
> > instead of running a docker build again.
> 
> Could we just have a script that pulls the quay.io image and tags it as
> the appropriate target and then we could do:
> 
>   make docker-image-debian-arm64-cross [REBUILD=1]
> 
> which would normally pull the quay.io image but if REBUILD=1 would force
> a local rebuild?

Perhaps, I hadn't really got as far as thinking about the make
integration side.

> 
> >> The other area that needs some work is better supporting non-x86 hosts.
> >> While Docker's multi-arch story is much better (docker run debian:stable
> >> will DTRT on any main architecture) we get stumped by things like
> >> Debian's uneven support of cross compilers. For 4.1 I'd like to
> >> reorganise the dockerfiles subdirectory into multiarch and arch specific
> >> directories so we approach this is a less ad-hoc way. It would also be
> >> nice to have the ability to gracefully fallback to linux-user powered
> >> images where the host architecture doesn't have what we need.
> 
> I suspect we'd never store linux-user powered images on quay.io as there
> are niggly differences depending on the users binfmt_misc setup.

Wouldn't we just upload the cross-build images and rely on the user's
host to have registered binfmts needed to execute foreign binaries
in the container ?

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|